The present invention is directed to methods and apparatus for detection, prognostic diagnosis, treatment and prevention of cancer and other hyperproliferative disorders in humans and animals. More particularly, the present invention is directed to vascular mimicry factors that are characteristic of tumors, cancers, diseased tissue and other disorders and methods and apparatus for detection and usage of such vascular mimicry factors. Such vascular mimicry factors can be used in the detection, diagnosis, treatment and prevention of such cancers and disorders.
It is well known that tumors exhibit various degrees of virulence (the tendency to proliferate, either at the primary tumor site or to remote, metastatic sites). While many tumors are slow growing and have little or no propensity to spread beyond the primary site, some tumors are highly aggressive. It is these rapidly growing, highly virulent tumors which are most dangerous.
A patient""s prognosis is generally good if a tumor is discovered early enough and especially if the tumor is not particularly aggressive. For example, if a tumor is confined to the primary site, a physician will frequently design a course of treatment with the intent to cure the patient. However, the patient""s prognosis is poor if a tumor is highly aggressive since the success rate for conventional treatment of such tumors is generally low. Thus, in such cases the physician is likely to design a course of treatment that is merely palliative.
Tumors that are growing aggressively require significant enrichment with various nutrients and oxygen to support their growth (which is very rapid relative to that of normal tissue growth). Therefore, such tumors tend to promote development of new vasculature, apparently in order to accommodate enhanced delivery of such nutrients and oxygen. It has been thought that this new vasculature was produced as a result of signaling agents produced by tumor cells, and that such agents would presumably serve to stimulate the growth of blood vessels into the tumor. It has furthermore been thought that the cells in this new vasculature were composed primarily of endothelial cells (i.e., cells normally found in and composing blood vessels) whose growth was signaled by various angiogenesis factors. Consequently, there have been significant recent efforts by several groups (such as those of Folkman, as illustrated, for example, in J. Folkman, xe2x80x9cSeminars in Medicine of the Beth Israel Hospital, Boston, Clinical Applications of Research on Angiogenesis,xe2x80x9d New Engl. J. Med 333 (1995) 1757-1763) to use agents that inhibit such angiogenesis via application of various angiogenesis blocking agents (i.e., agents, such as endostatin and angiostatin, that inhibit the formation of normal vessels). Unfortunately, the effects of such angiogenesis blockers is not limited to tumor vasculature, but instead also inhibits blood vessel formation in normal tissue.
Hence, for improved ability to treat tumors, and especially aggressive, virulent tumors, it would be desirable to have agents that could selectively block formation of neovasculature formation in or around tumors without affecting normal vessel formation in healthy tissue.
The inventor has discovered that new vasculature in aggressive melanoma, prostate, glioblastoma and other tumors is produced from tumor cells (rather than from endothelial cells entering from outside the tumor), in a process termed xe2x80x9cvascular mimicry.xe2x80x9d As a result inventor has found that certain individual genes and/or gene products, termed vascular mimicry factors or VMF, responsible for the formation of such vessels can now be identified using tissue culture and differential gene expression profiling methods, such as those disclosed in applicant""s co-pending provisional application No. 60/151,406 with a filing date of Aug. 30, 1999. The present invention is directed to such VMF, and to methods and apparatus for identification, detection and usage of such VMF. The present invention is further directed to such VMF as the basis for development and manufacture of various diagnostic, prognostic and therapeutic products capable of selectively detecting, characterizing, treating or preventing such tumors.
The present invention has been made in view of the above circumstances and has as an object to identify VMF in various types of metastatic cells. A further object of the invention is to isolate and purify these VMF and to develop diagnostic tests for use in determining if VMF are present in a suspect cell line. A further object of the invention is to identify targets for anti-tumor agent development and manufacture. Further objectives include the creation of molecular vaccines and immunotherapy based on the VMFs. Additional objects and advantages of the invention will be set forth in part in the description which follows and in part will be obvious from the description, or may be learned by practice of the invention.
Thus, this invention contemplates a method of assaying for vascular mimicry factors comprising: isolating invasive tumor cells, isolating noninvasive cells, determining types and amounts of differentially expressed sequences using a microassay technique, and comparing the invasive and the noninvasive cell expressed sequence profile. It permits assaying for the presence of vascular mimicry factors using a serum antigen capture assay comprising: attaching to a solid phase an antibody elicited by injection of a vascular mimicry factor into an organism; incubation of the solid phase with media suspected of containing a vascular mimicry factor; incubation of the resulting product with a conjugated antibody to a vascular mimicry factor; determine the presence or absence of vascular mimicry factor. The invention permits a method of developing an immunogenic response in a patient comprising screening a suspect tumor in said patient for a vascular mimicry factor and raising antibodies to said vascular mimicry factors in said patient. When the vascular mimicry factor is placed in an expression vector, the product can be easily produced and used. Moreover, the inventor""s discovery that VMFs are made by the actual tumor cell and not by endothelial tissue indicates that a method of assaying for the metastatic potential of a tumor cell can comprise growing suspect tumor cells in the absence of endothelial cells in a restrictive cellular matrix media and observing the production of vasculature-type structures.